CORE LAB ONLY - NO SUBJECTS THIS PERIOD This study seeks to examine the relationship between a peripheral index of serotonin (tryptophan/amino acid ratio) and history of impulsive aggressive and/or suicidal behaviors in patients with DSM-III-R personality disorder and healthy age/sex matched volunteers. During this period 63 samples were assayed for Neutral Amino Acids and 65 samples for Tryptophan.